Just found a little strange thing.

Water grass can stuck wolf. Maybe it can do it with other animals or mobs?(i don't test it on other mobs)

What I expected to happen was...:
nothing?

What actually happened was...:
wolf stuck in one place - in block with water grass. All what he can - jump up for breathe and circling around.

Steps to Reproduce:
1. "find a water grass"
2.  get wolf on water grass
3. wolf stuck.
4.after broke grass wolf get free.